On our internal discussion list, someone just asked about how to pass switch parameters from one function to another. This person asked this as "Why can’t [switch] parameters be passed as parameters?".<\/p>\n
My short answer was simple: "They Can Be"<\/p>\n
Answering this question is a great way to illustrate the value of a PowerShell V2 feature called Splatting. Splatting is two things, it’s a way to get all of the parameters passed to a function automatically (they’re in a variable, $psBoundParameters), and it’s a way to take a list or dictionary of arguments and pass them on to the next function below.<\/p>\n
The mistake of trying to pass along a switch parameter is a pretty easy one to make. [switch] will let you specify the parameter by just passing –ParameterName<\/em> instead of –ParameterName <\/em>True.<\/p>\n When you try to pass on a value to another underlying function, –SwitchParameterInOtherFunction <\/em>$switchParameterInThis function will set the switch to true in the underlying function, and then pass a positional parameter with the value of the switch parameter.<\/p>\n The V1 fix for this is to put a : between the parameter name and its value. The V2 fix for this is to simply use splatting. The important line below is in bold and italics.<\/p>\n